Journal of Geo-information Science >
Clipping Computing Model for Vector Map at the Layers’ Level
Received date: 2013-01-14
Revised date: 2013-04-24
Online published: 2013-08-08
Clipping function is one of the fundamental functions in Geographic Information System. The efficiency of clipping function can greatly affect the overall performance of data processing in GIS application, especially when clipping large vector data. This paper proposes a new clipping computing model to effectively fulfill the clipping function for different types of clipped layers according to their different attribute and geometry characteristic, such as point, line, polygon, multi-point, multi-line, multi-polygon and so on. This clipping computing model consists of the following three steps: first of all, using clip-layer's Minimum Bounding Rectangle to select features from clipped-layer, where the features must intersect with or within the clip-layer's Minimum Bounding Rectangle; secondly, using Feature ID to build revised quad-tree index for the clip-layer features; lastly, using thread-pool to fulfill clip computing in parallel. A performance test was carried out using four different vector data layers. The result shows that the performance of clipping function based on this clipping computing model is as efficient as the one fulfilled in ESRI's ArcGIS 10.0. CPU-intensive is one drawback of the implementation of this model at its current form.
Key words： computing model; layer clipping; thread-pool; vector map; quad-tree index
WANG Qiang-Gang, TIAN Sheng-Jun, FAN Xie-Yu, YANG Yan-Jing . Clipping Computing Model for Vector Map at the Layers’ Level[J]. Journal of Geo-information Science, 2013 , 15(4) : 532 -537 . DOI: 10.3724/SP.J.1047.2013.00532
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